This invention relates to the field of work-holding clamps, and in particular to those work-holding clamps applying pressure all in one plane for light to moderate duty applications.
Earlier clamps in this field, while well-suited for the purposes for which they were intended, have been very limited as to their scope and range of use. For instance, Naglee, U.S. Pat. No. 242,959, issued June 14, 1881, probably represents one of the original edge clamp patents. All threaded members shown are rigidly attached, and the uses to which the clamps can be put is thus limited to holding an edge portion against a main portion until the glue holding the two pieces together dries.
In Ostling, U.S. Pat. No. 2,366,350, issued Jan. 2, 1945, the arms holding the screws are allowed to move relative to each other, but each screw is still rigid with respect to the arm holding it. This again limits the usefulness of the clamp to holding a T-joint in a glue-drying function.
Finally, in Hewat, U.S. Pat. No. 2,642,905, issued June 23, 1953, one of the screws is allowed to move and pivot with respect to its bracket. This allows it to be used as an edge clamp on more irregular surfaces, although it is essentially limited to that function.
This invention relates to improvements over the above clamps and to solutions to some of the problems raised by their limitations.